XIAOMI m365 BMS Problem - Wrong Bank Voltages Shown

My problem was the following: two banks/cells were showing weird voltages - I measured them and the actual bank voltages were fine.
This ended up severely restricting the usable capacity of the battery pack: the erroneously low bank would cut the entire battery early, while the erroneously high reading bank would cut the pack early on the charge cycle.

[@kiri4470]

Thank You! I had a problem that the BMS was dead, I charged all cells to the same capacity, welded the cells (it worked fine), and after a few days there was a problem with cell 9 and 10. Cell 9 was showing 4,5V, and cell 10 was showing 3,5V. After desoldering CF1 everything came back to normal.

[@pauliusnesakysiu6393]

Thank you for the advice. I had an 8-cell problem. I changed all capacitors to CF1-11. after the change, I drove 16 km with a 75% charged battery. Before replacing the capacitor +- 6km mileage and shows that the battery is discharged.

[@secureguard673]

u couldn't have found a better time to clean up the screen, perfect spray for every BMS occasion, seeing better is more important than battery fire, great job

[@cbrunnkvist]

Excellent, very good explanation of your troubleshooting process. One of my M365's suffered either a cell/group failure or a busted BMS, never figured out what to replace. Might give it another look under the magnifying cam ;-)

[@nikstoun]

Thanks for video, same problem i have too, B10 wrong voltage show bms ..blink red 4 times and not charge. But in my case i remove CF 1, its show difference when measure comprare to other capacitors. Now is back to charge :)

[@stefanputureanu9296]

Thank you. Same problem here. Cells measuring good on multimeter (all at 3.65v) and BMS reported one cell empty - 3.1v and one overcharged - 4.25v. Measuring on the BQ inputs - voltages where right as the BMS reported. First i have removed all caps from all BQ cell inputs (same problem) and then i removed the BQ chip (voltages got good on chip pads), then i have put the BQ chip back and removed all zenner diodes from the cell inputs - problem solved. My BMS had zenner diodes in parallel with the caps... on the multimeter the diodes measured good - 0.5v voltage drop - no leaks, but they influenced the chip somehow. BTW BQ chip is hard to measure without an oscilloscope... the inputs are oscillating between measurements of the cell (high impendance - normal voltage of the cell) and calibration of the cell (low impedance - voltage dropped). Now the battery is like new: it keeps a good charge and is charging normally. 👍

[@2mend]

Hi I also have weird readings and the min max difference shown by the app is twice bigger than the actual readings. Also readings in the app are jumping between two cells randomly back and forth. Did you edned up with both capacitors and zenner diodes removed?

[@stefanputureanu9296]

​@@2mend Yes, but that was not the fix. It might be that resoldering the BQ chip fixed the problem for a short period. After a week i had the same problem. I ordered a new BMS from AliExpress and now is fine.

[@orkizozi]

great video. I had the same problem as in the video. turned out the problem was on one of the tiny resistors on the battery pack. I replaced it and problem solved. thanks

[@Conservator.]

Nice analysis and repair. 👍

[@Serwis_Elektroniki_]

Yesterday I repaired the battery with the same problem. Only today I started to google if this is a common problem and it turns out that not only I was doing it: D.

[@Darieee]

alright - nice! same cap? at the time I made this video no one else seemed to have complained online

[@Serwis_Elektroniki_]

@@Darieee Yes. Same cap!

[@steffenrbkhingelorentzcars3542]

Hey do you have a link to the diagram for the m365 bms?

[@metaeditors]

Very good down hunting

[@berberger4814]

6:05 thank you for confirmation, I noticed that behaviour with the glasbed of my printer, but I was not sure btw is that an Ipad 7 or 8? cause I got the 7 and the oleophobic coating on mine is not that good compared to others, maybe I should reapply it, did you notice that as well?

[@Darieee]

I'm super happy with the coating on mine a it's a 10.5 pro I think

[@kocakapo1]

Ich was looking for a solution. I think i have the same issue. thank you for the video

[@Ciarkaz]

Thanks, i've solved same problem on my ES2 internal battery (they have same circuit but packed in different layout).

[@Darieee]

same shifted voltage due to smd caps failing, huh ?

[@Ciarkaz]

@@Darieee yeah, I've lefted it to charge overnight and soon I'll see results

[@Darieee]

let us know how it turns out !

[@Ciarkaz]

@@Darieee It worked like a charm. Do you know capacity of these 0603 capacitors?

[@Darieee]

not off the top of my head - but the chip's datasheet has values for the typical application - so - go off those if you really want to put some back on

[@removecrypto3462]

Hi thanks for youre video. So you just renoved that cap?

[@Darieee]

yup

[@MakerFabio]

Hi tha ms the the glod video Which application is showing ea h cell voltage? Do gou know which component is the regulator for the microcotroller, i have totally no action, no blinks

[@Darieee]

m365 tools shows all bank voltages

[@Darieee]

no idea where the regulator is tho ☹️

[@MakerFabio]

@@Darieee thanks , i can not find m365 tooks for iphone. I see m365 dashboard, m365 go, m365 plus. (All woth terrible reviews). Are you using apple devices?

[@Darieee]

I also run an iphone .. buuuut .. yeah - you need be borrowing an android for these scooter specific applications iOS has nothing to offer on this front ..

[@MakerFabio]

@@Darieee many thanks

[@lucacavallini561]

If i understand, if i have pack not allineated, i must remove the corrispondent capacitor in that line Array?

[@intuicio]

Hi! I have same problem, but at the cells 2 and 3… On cell 2 I have 3.55V and on cell 3 I have 4,12V. All other cells have 3.8. I have alse measured everyone and all of them are same voltage. What will fix my problem? Same issue everyone? Thanks!

[@Edwintongol80]

Hello darieee, have you ever know what is issue with the fast dried battery , after I ride 5 minutes the battery 8 %to 9 % less battery charged

[@petr5178]

Hello, I have same problem, but at the cells 4 and 5… On cell 4 I have 3.5V and on cell 5 I have 4,25V. All other cells have 3.9. I have alse measured everyone and all of them are same voltage. What will fix my problem? Same issue everyone? Thank:)

[@jessemorton]

I'm having the same issue as you. Did you fix it by any chance?

[@RuiSjm]

Charge that bank with external lipo charge, that is because your cells are unbalanced.

[@archminael]

​@@RuiSjm did you read carefully? He said that have the same problem like in video but in other banks. He measure banks and they are even, only BMS show different values

[@RuiSjm]

@@archminael oh, sorry, my bad!!

[@KannyLive]

Is this problem after flashing the scooter?

[@Darieee]

no - this problem has nothing to do with flashing the scooter

[@ruslansdakuzasvili1176]

I got problem too with charging , was unable to charge battery ,but i was turned on but worked slow and all of the dots count from to one dot ,after removing this capacitor ,scooter not turning on anymore ,battery woltage is ok ,i charging battery with original scooter port ,but without the bms ,and it charging fine ,i guess its Bms gone bad..

[@FxkDGM]

Any idea where I could find the bms error codes for the xiaomi? If not do you by any chance know what it means when the bms is flashing red, then blue and red a few times and finishes off on a single red?

[@nikstoun]

It's don't need. If end with red mean that bms not see all 10 groups.Start measure from each point B0-B10 to CF1 - CF10 capacitors on PCB. But first uncut from battery B0-B10

[@siriotec3752]

433 / 5.000 Risultati della traduzione hi, i have a strange problem with m365, when i connect the charger, sometimes it starts, sometimes not, when it starts after 5-8 minutes it turns red, sometimes it resumes charging by itself for half a second, then red again, it seems bad contact, I checked all the welds of the battery, and they are attached well, I also tried to buy another charger, but it does the same problem, do you have any suggestions thanks

[@sahiska]

me checking the electricity bill: please don’t be high electricity bill: 02:17

[@Darieee]

🤣

[@danielherda8503]

Do you know what specs are all CF1 - CF11 capacitors ?

[@Darieee]

not off the top of my head, but the datasheet does suggest values - most likely xiaomi used those

[@ZenyWorld]

Same here. 9 and 10 fucking banks. I see the Xiaomi should be fined for selling scooters with factory issues and no recalls. Xiaomi no more in my home.

[@Darieee]

I don't know about that - thus far I haven't seen anyone build better scooters - do you have any suggestions? mine also died and keeps dying because I draw 1.1KW out of it, instead of the factory default of about 6-700

[@kexcelkexel1443]

Video reparando es2 la bms